Variable velocity impact testing machine



April 16, 1946. J. J. KANTERE-r A1. l 2,398,746

\ VARIABLE VELOCITY IMPACT TESTING MACHINE Filed July s, 1942 y l9 sheets-sheet 1 April 16, 1946. J. J. KANTER ETAL VARIABLE VELOCITY IMPACT `IES'TING' MACHINE Filed July 8, 1942 9 Sheets-Sheet 2 April 16, 1946. J. 3. KANTER ET Al. 2,398,746

, VARIABLE VELOCITY IMPACT TESTING MACHINE A Filed July 8, A1942 v9 sheets-sheet s April 16, I1946.

yJ. KANTER ETAL VARIABLE VELOCITY IMPACTL TSTINGMAGHINE Fiied July s, 1942 9 Sheefs-Sheet 4 April 1 6, 1946. 1J. KAMER Em, 2,398,146

VARIABLE VELOCITY IMPACT .TESTING MACHINE Filed July 8, 1942 9 Sheets-Sheet 5 April 16, 1946. J. J. KANTER ETAL 2,398,745.

VARIABLE VELOCITY IMPACT TESTING MACHINE Filed July 8, 1942 9 Sheets-Sheet 6 JOM@ @hf/f0.7

April 16, 1946. J. J. KANTER ETAL l VARIABLE VELOCITY IMPACT TESTING MACHINE V Filed July va, 1942 9 sheets-sheet 7 L.; Lz I Hiw- April 16, 1946.l .1.J. KANTER Er-A| VARIABLE VELOCITY IMPACTy TSTINGMACHINE Filed Julyv 8, 1942 9 sheets-sheet a April 15, 1946 J. .LKANTER 1-:1- AL 2,398,746

VARIABLE VELOCITY IMPACT TESTING MACHINE Filed July 8, 1942 9 Sheets-Sheet 9 ililmwgll Patented Apr. 16, 1946 s UNITED STATES PATENT o Fries VARIABLE VELOCITY IMPACT TESTI G MACHINE Jerome J. Kanter, Palos Park, and Watt V. Smith, Chicago, Ill., assignors to Crane Co., Chicago, Ill., a corporation of Illinois Application July 8, 1942, Serial No. 450,206

(Cl. i3-101) Claims.

measuring the change in kinetic energy of the moving mass. Or, to express it differently, meassurement is made `by this type of machine of the energy absorbed by the particular test specimen upon being struck by the moving mass.

There are several types of impact testing machines available but none of these has proved to be entirely satisfactory especially insofar as impact testing at variable speeds is concerned. Probably the better known of such machines is the pendulum type of testing machinewhich is used for the testing of small specimens whichare placed horizontally with the Aends supported by an anvil.

machine which is accurate, mechanically efcient and is convenient and easy to operate under all conditions. It is true that machines for variable velocity impact -testing have been previously designed, but thes'"`prior machines have beensub-` ject to serious criticisml from mechanical con` siderations and none of them has givenA recordings satisfactory for interpretation as to the energy absorbed by the specimen during the test.

Another important object of this invention is to provide a variable speed impact testingmachine which employs an automatic specimen insertion means that nsuresthe proper positioning of the specimen to be tested. The specimen is brought to rest at a point immediately below the striking edge ordog onthe impact wheelinless The hammer vstrikes the test specimen midway between the supports and after breaking the specimen continues its swing upwardly. vThe energy expended in .breaking the specimen is a product of the weight of the pendulum and the difference The pendulum machine is however limited in the scope of its usageinasmuch `as the velocity of the pendulum for a particular machineris substantially fixed and may be varied only slightly. The

impact testing machines is usually about 15 feet per second. It has been demonstrated in research investigations that the impact resistance strength of a material is a function of the velocityV of impact as Well as of temperature, and that for each metal there probably is a critical velocity which, if exceeded, causes the material to appear brittle. Thus the terms tough or brittle as applied inthe description ofthe properties of any material are merely expressions relative to the velocity at which the materialis tested. The real problem in impact testing is to determine how far the critical velocity which renders the material brittle in behavior is removed from the contemplated service velocity rather than comparisons of impact.

y between its height of fall and theheight of rise. r-

i relatively fixed velocity of the pendulum types of than one-half revolution of the wheel regardless of the speed of the impact wheel; The latter arrangement thereby prevents anyA attempted insertion of the specimen simultaneously with the passing of the impact dog which might otherwise be the cause of an accident.

4Another important object of this inventionlies in the provision of a novel indicatingmeans for the energy change in the variablevelocity impact testing machine during a test which includes a D. C. generator directly operated by the multispeed impact vwheel and arranged to act as a tachometer. A vacuum tube amplifier circuit used with the tachometer circuit allows for the quan-- tity of current generated to be recorded on a microammeter, and a freezing of the pointer of the microammeter occurs immediately after the breaking of therspecimen whereby a stationary indication of the reduced current is registered in 1 microamperes. Since the change in energy results in a change of speed anda consequent change in E. M. F., the difference in microampere readings before and lafterbreaking, the specimen thereby denotes the amount of kinetic energy absorbed by the specimen when broken by the novel variable .i come apparent from the disclosures in the accomvelocity impact rotor. i

Another and still furtherimportant object of this invention is to provide avariable speed motor for driving the impact wheel through a clutch arrangement and a solenoid operated in cooperation with the clutch to automatically disengage the motor from the impact wheelbefore the test specimen is fractured.

Other and further importantA objects will bepanying drawings and followlng'sp'ecication.

In the drawings:

Fig. lis a front assembly view of the variable velocity impact machine of this invention.

Fig. 2 is a rtop plan view of the machine as shown in Fig. 1.

Fig. 3 is an end elevational view of the machine of this invention.

Fig. 4 is a fragmentary view'of the specimen 5 vanced to a cocked position. l

Fig. 6 is a view similar to VFigaro of the test V- specimen positioning means with the specimend at the impact or breaking position.

Fig. 7 is a front view of theinstruinent'panel of the variable velocity impacttestin-g machine 1'5` of this invention'.

Fig. 8 illustrates the wiring diagram. for the speed change amplifier used in this machine.

Fig. 9 shows another wiring diagram of the photoelectric. Vcell amplifier Cir-@gt used .inwnzo junction with. the oper-aufm. Qfihis machine Fie. 10 Vis an enlarged. :freemeniary--.seiienal View through the center- 1of .-t h e.,.rctor vof .this machine; and showing the positioning device with the specimen in its breaking. position as shown Y in 25 Figli. Y

Fig. 11 is a sectional view taken ontheline IIII ofFig.10. j rig... 1.2 isa fragmentary sectional View. Similar toV Fig. 10 and incorporatesa tensiletype of test 30 specimen.A

Fig.L 1.3 a. Sectional View taken.. the. 11.11 13 -13 ofrig. 12,

Fig. lflis agfront elevation ofthe test specimen holder partially insertion..

Fie. 175 isaside .elevation 0f the. Specimen. .helder as.sliovsnin.1iig.1f1, .e

Fie. 1 6 isa. plan view-.Oi .the Specimen holder shown in Figs. 1 4v Vand 1 5,

Fig.. 17show s a novel triggermarm -used in con- (ifo base lor the like Yfor supporting thevariable velocity impact testing machine. The latter device 50 comprises `a 'main framework. l21 upon. which `is mounted the journaling bearing blocks: or supports 3, 1,26 and 1., suitablyaligned to receive a shaft f8 therethrough.` The'shaft 8 is divided by a clutch 9 into the segmentsz and 'Ill-. A series 55 lof shea'ves II arewmounted between thefbearing blocks 3 and Ali and` positioned on the segment 5 of the shaft i8, the sheaves` havingY vs-shaped grooves and adapted to be ldrivenbythe. belts 'I2'.

A hand brake lever lIii-"is provided Afor the :purpose 60 of slowing down and stoppingl lth'eishaft-segment -ll when the clutch i9 is disengaged. Mounted betweenV the -bea-riii'gfblocks 6 "and L'I .is themain 'rotor' -Iill vover 'which there `is vpos'itiorlied1aguard The loading lever 2|, as laterde'scribed, .is pref- 70 erably 'not 4rigidly 'connected #to gthe shaft I9. Fbut merely has a spring connection:therebetween,v and the basefof the lever 2|,A as shownat 2- El ,..is.-jour naled ongthebearing 24--surroundi-ngthe :shaft I9. The superimposed shaft or lever base 2li is 75 .inspection or -the like.

maintained in its several positions by the pawl 22 pivotally attached to a portion of the frame 2 and which engages the notches 23 in the member 20. A lamp 26 is provided to excite a photoelectric tube. A coupling 2l joins the shaft l0 to the gear 28 upon which the rotor Ill is keyed, which thus operatesthe `direct current generator 29. The photoelectric amplierlis-designated at 3l. After being struck by the rotor, the severed portion of vthe test specimen will be traveling at high vej-lpcity. Therefore -a receptacle 32 for catching the'broken pieces o'f the test specimen is provided within the base of the machine I. The drawer or receptacle 3 2 is `s1idably movable transversely within the 4base Aby manual actuation of the handle 33 'so as to permit 'withdrawal of the specimen for The drawer interior is suitably .padded so as to prevent injury to the specimen from the impact when it is received therewithin.

Referring new to Fig. 2 'of the drawings, the .Vebelts yI2 are preferablyfdriven by a variable speed `motor 34 Ydriving the `pulley or sheaves 36. The clutch 9 is equipped with a sliding jaw 3l mounted on and rotatable with the shaft 5 which engages the stationary jaw 38, a unitary part of the sha-ft I0. The sliding jaw 31 is `actuated by means of the lever arm 39 and may be .operated either manually bythe yhandle AlIIor els'eelectrically by means of -the solenoid 42. The latter member, when energized, causes tne rocker arm 43 to disengage Ythe pin v`lion the arm 39, thereby permitting the lspring Mito pullthe lever arm 39 towards its anchor postdl I'about the .pivot point i8, and thereby Aeffect a disengagement of the sliding clutch..jaw 3.1 .with the stationaryV clutch jaw .33. 'Ac'lutchk indicator switchf49 is actuated bythe spring 5I, being expanded -and contracted by means of the lever arm 39. 'The brake handle and the lever- If3 iis pivoted about 'apoint 152 and acts-Ito lift the semi-'circular brake band 53 upwardly against the underside ofv thefshaft I0.

V'The inip'act wheel I4 is shown `in .more detail in fFigscB, 4,15-, 6, 10 and 12 and, as Acan be seen, -is preferably equipped 'with diametricall'y -opposed striking dogs vtill extending outwardly 'from the periphery thereof. At-the vfront end ofthe rotor or impact wheelfl an anvil 5'6 'is positioned as `better Shown in Figs. 10 and'l-"l', andupon which the test specimen FI vof thematerial to vbe tested is placed.V lBy means hereinafter described at lengtln'it is thereupon injected -closely adjacent the periphery jofjtheimpact rotor If'I at Va predetermined Atime other than when either of the impact striking dogs 54 is passing Athe immediate location "of the anvil V56. In order to effect this very accurately timed operation 'a photoelectric cell 51 is .provided which is actuatedbythe'reflection of the lamp 26 Afrom a predetermined shiny portion on the side surface ofthe rotor I4. rIhe Aenergy voccasioned tby this reected light is amplified 'by the photoelectri'c cellamplifier circuit as Shown at 3`I, arid as Set 'forthln more detail in Fig. 9. l

'Ihetest spe'cimnloadin'g mechanism as shown in Figs, 4, 5,6, 10 and '-12, isprovded with 'the 'hand lever `2II and base 'member ZI) rotating Yabout the bearing 24 whichtelescopes the internal shaft I9 to which the specimen holder I8 lis bolted by means of the threaded shank 58, as best shown in Figs. l0 'and l2. The test specimen of material ish-of `a recognized or standardsize andis posi- `tioned in theholder IB when-the lever handle 2l is in an upright'position as shown'in Fig. 4. The

test specimen I1, as shown in the latter ligure, is` positioned in the holder I8 and Iis held firmly in place by the guide pin 62 and a ball 63 under compression by means of the spring 59 and the adjusting screw 6| (see Fig. 14).` The holder I8 is equipped with a dovetailed tongue 64 running across the back thereof and engages asimilarly shaped groove 66 in the rectangularly shaped member 61, thereby forming a dovetailed slidable joint. The latter arrangement permits accurate positioning of the specimen holder with relation to the anvil 56. After the holder has been properly centered, the set screw 68 is` tightened and thus prevents further movement `of the specimen holder with reference to the connection between the holder I8 and the shaft I9. K e

'The connection between the holder I8 andthe shaft |9,consists of the shank' member 58 which threadedly engages the shaft I9 and the member 61 to which the holder I8 is immediately attached; with the coupling 69 therebetween. As best shown in Fig. 14, the member 61 supplied with a slot 'II is permitted reciprocable movement upon the pin 12 which is fixedly attached to the cou# pling member 69 and limits outward movement of themember 61 from the coupling 69. The coupling 69 is provided with the shouldered bore as shown at 13 to limit'the inward movementof the member 61, and also provides for the housing of the spring 'I4 in the reduced bore diameter. The spring 14 thus acts to push the member 61 outwardly to its maximum positionas determined by the pin( 12. The foregoing arrangement provides the specimen holder with a much desired ilexibility when the specimen I1 and theholder I8 are brought down upon the anvil 459, asbest shown in Fig. 5. Otherwise, as is evident, it would be very diiiicult to adjust the length of the connection member between the 'shaft' I9 and the holder I8 so that the specimen would rest completely and solidly upon the anvil 56.` Without the flexibility referred to, the attempt to adjust thetest specimen and holdervwould result in its resting vat a position above the anvil in order lthat thespecimen holder I8 would not` be damaged if the adjustment were vtoo long. Subsequently, however, upon movement into position upon the anvil, it would strike the anvil and cause damage thereto. Completing the description of this novel arrangement, the threaded shank 58projects into a bore 16 at the opposite end of the coupling 69 and is held in place by the pin 11 (Figs. 14 and 15.).

Per Figs. 2` and 3, the loading lever 2| rotating about the line bearing 24 is provided with the bracket 18 integrally mounted thereon and on its outer extremity the two-part electrical switch 19 is mounted with an actuating button 8| `beneath the bracket arm 18. Accordingly,4 the switch button 8| is actuated by the right end portion of the apertured trigger arm 90 as shown at 82, the trigger arm being mounted relatively non-rotatable to the shaft I9, as indicated. As hereinafter described in greater detail, the modified trigger arms 9|] 'and 90 shown in detail respectively in Figs. 17 and 18 are selectively attachable to the central shaft I9 at 83, dependingv on the type lof test desired. A rocker arm or pivotable lever 84 is mounted on the framework, as indicated at 86, with the lower end of the lever arm being attached as at 81 to the core 88 of the solenoid 89, all of which is more clearly shown in Figs. 3 to inclusive of the drawings; The upper extension of the rocker arm 84 is lprovided with a catch or lug 9| which, in its normal positiomserves to hold the leftend of the trigger arm 92 in a restrained position when the loading lever 2| is being maintained in the cocked position, as shown in Figs. 3 and 5. s best shown in Fig. 4, in the loading position the trigger arm 98 is preferably offset from the loading lever 12| by lan angle of' approximately 20 degrees and in e Alever arm 2| togetherwith its associated bracket 18 is rotated aroundto a horizontal position, as shownin Fig. `5. During the largerportion of the said latter movement,A the'shait I9, the member 2B, and the Vlever 2| move as a unit. until'such time as the left end portion 92 of the trigger arm 98 contacts the lug 9| `on'the rocker arm `81|t Concurrently with such contact and continuing on downwardly tothe horizontal position of the lever handle 2|, as shown in Fig. `6, the internal shaft I9 remains stationary. The latter `independent movement of the loading lever 2i there*- upon causes the switch actuator 8 I to be comjpressed by the end 82l of the trigger arm, as shownin Fig. 3. Immediately upon actuation of the solenoid 89 its core 88 is drawn inwardly and similarly the `lower end of the rocker arm 84 is drawn with it. Thus the rocker. arm 84 is pivotedabout the point 86.50 that the catch 9| is moved to the left and the end portion `Stof the trigger arm V9|) is permitted to pass upwardly which simultaneously `accomplishes a, release of the switch actuator 8| and an opening of the switches 19. e f

As shown more clearly inFig.. l0, the simultaneous movement of the shaft I 9 and the mem ber v2|) is effected by theiruse of a novel spring connection which employs the studv 93 threaded` ly engaging tl'xeeinternal` shaft I9 and its` outer end attached by means'ofa spring 94 to an eye bolt 95 threadedly engaging a dependingportion 91 ofthe outer shaft 20 and theintegral loading lever 2|., Upon the loading. lever 2| reaching the position asshown in Fig. the trigger arm 90 will then be subjected to spring tension by reason of the fact that atV thisfpoint the shaft I9 has, beenseparated or restrained fromv movement with the lever 2| and its superimposed shaft basenmember 2|) tok a position' in which the spring 94 has 'been' ,fully extended. Hence upon retraction ,of the lug 9|, the inner shaft I9 is enabled to :resume its' normal relationship' with the lever 2| and the outer shaft 28 becauseof the spring 94 resuming its normal position and degree of extension. The rotative movement of the internal shaft'IS is limitedby the arrangementof the trigger arml striking the adjustable stop 98 as bettershown in Fig. 6. At this stage the test specimen I1 and its holder I8 have beenA moved toa position closely adjacent the external periphery of the rotor I9. The inward' movement of the test specimen I'1 is further limited bythe guide pins 99 positioned in both sides of the anvil 56. lThereafter upon de; energizingthe sole'erioid` 89,4 the spring` IElI pulls the rocker arm '84back to its normal substantially vertical position.` At this time, the pawl 22 and its manually operable, upwardly projecti ing arm |02 is'held' in a forward position and is maintained "within the slot 23 by means of the spring |03 attached to the fixed pin |99.` Directing attention now to Fig. 8, the change speed amplifier circuit shown therein'is designed speed! of the rotatingdisc It. Anerangeui:

- rent is supplied? at |08' and ciirsesthdugh a transformer |||9` to a rectier tube for conlverting alternating current to' direct Vcin-rent and;A inaddition, the fwd Vltagerll'tlb |2 combin to furnish a ClSIii dl'ff Crt voltage. The directc'urrent g'erreratr-.29'y which is geared directly to the shaftof the impact ina'- chine, has an output'thatis piportional tftlie speed of the machine.. The'. output of this inachine is opposed to the output ofa vseries of'vs'iii 11A, volt dry dry cellsr'shown at ||3', lthroiiglfia pair of variable resistances |`|4 andV |1|6` that enables` a very small difference in potential' to be establishedk between the outputl generator 29 and the dry cells ||3. rh-is differencey in potential is constant so long asv the speed ofv theshatt I'llV remains constant, but readily varies with any changes in the speed-of' the. shaft'.` This differ ence in potential is applied to the grid ofthe pentode tube ||'1, which is' arranged `in parallel with a sirnilar pentode tube H. The correspending grid in the tube ||8 is held at a cori- 'stant potential by use ofa 11/2v voltV dry cell shown at ||9`. Power is supplied. to the plate ofthe two pentodetubes l|1 and |`|8 from opposite ends of av Variable resistance |2|-, which arrangement permits establishing a` small constant di'ierence in potential between` the. rtuloe plates l when the gridsv are maintained at a constant potential. The series wired microammeters |506 and' |01 are connected across the plates to measurev the flow of current caused by the difference in potential between the plates.` of the tubes ||1 and H8. Any, variation in grid voltage on the ||1 tube is am-v plified and indicatedby the microammeters |06 and |01. Such a variation wouldbe vcaused byva change in the speed of the shaft-mf which iny turn is caused by the energy absorbedl in the breaking of the specimen |1 by the impactof the striking dog 54. The difference inymicr'oarnmee ter readings after a definite time interval; ob=

tained when slowing down without breaking a 'specimen and that obtained after the same time interval when a specimen-is broken. is taken as 4 the` index to the materials'A resistanceto fract'u're. Themicroainm'eters llliand |01 have a Variable sh'unt resistance |2`2`inpa'1allell therewith and another variable rheostat .|Z`3for balancing the microammeters. Theintroductionof one ormore of the six 11/2 volt dry cells shown at |`|3 is accomplished. by the range switch |.24 as shwn in' Fig. 8, and also on thecontrol Vpanel of Fig'. 7.

'he photoelectric amplifier 35| isconcerned-withinserting the specimen |'|'v into the pathoi the moving striker 54 ai, the proper time andi with maintaining the reading. ofthe microam-meter |01 after a denniteintervalwpf time best shown in the wiring diagram-of Fig-.-9;-the photoposition andY upon closing the panel switchI |-29the A circuit is completed through the breaking switch 19a,. thence through the coil ofv arelay |3|, and subsequently through the breaking switch; 191)-,v t the plate of the pentode tube-|32.- The latter tube' will not pass current unless the grid cnv trailed bytheprnieicme ceu' s. is at the proper greens potential. The plitoelectric cell 51 is supplied with current-frein a variable resistance |33 and permits" the passage of current only when a light ban falls on the tube element. This light beam from the lamp 2`6 is controlled by brightly'polishec'iv areas |3'4 (shown on Figs. 4, 5 and 6) on the iin of theiin act wheel |`4 and is flashed 't theploto'elctric c'ell with each half revolutdn ff thel wheelr thereby providing for one or the th'er striking dogs" 54 to engage the test specig nien l1. Y p A This energizing ofthe photoelectric cell 51 per'- rnit'sthe passage of current through the pentode tube |32 and energizes' the coil of relay'l3l, causing the amie-ctsv 135,-. lss to close .and thereby actuate the breaking solenoid 89 toV operate and release the trigger of the impact machine thereby causing the specimen to be 'placed in thepath of the striker 54 at the proper instant. Thel latter movement of the trigger arm 90 causes the' switches`19'a and 19h to open and' release the contact of the relay |3| and the relay |31. The relay |31 controls the solenoid |38 which establishes the microammeter reading as shown on microammeter |01' by means of alinka'ge |39 operativelyconnected to the core (not shown) ofthe solenoid |38 and the cross arm |40 which actst to hold the meter pointer`|44 in a stationary position. The condenser |4| retainsV suicient voltage to continue' to actuate the relay solenoid |31 for a definite interval of time before allowing the contact points'l42 and |43 to close' and to thereupon cause the solenoid |38 to x the posi'- tionof the pointer |44'oi` the meter |01.' An additional supply of electric current is placed into the circuit, as indicated at |46, and is controlled bytheswitch |41. When the switch |41 is closed it acts immediately to energize the clutch solenoid and thereby disengage the clutch and allow the rotor I4` to operate freeof the motor 34. The meter position-'nxing solenoid |38' is positioned in series with the` line |46, in contradistinction to then clutch solenoid 42iwhich is in parallel with menne |45'. inasmuch es theswiteh aarwhich acts to operate the disengagement of the' clutch bymeans of the solenoid' 42) is not employed until such tiniejasthe specimen holder and loading levi are n cocked position, as' shown in Fig'. 4, the-circuit' supplied by the 'electric 'current at |46 is not completed', atleast insofar as the positionii'kin'g solenoid is concerned, because the solenoid |31` is energized and has caused the contact points |42 and |43 to separate, making a breakin the circuit; Attention is directed to the fact that upon releasing the trigger arm 9|)Y the switches 19a and 1.9brresume their normal open' positions and as soon as the residual energy is absorbed from 'the condenser |4| the contact points |42 and |43 resume their yrnorma1 closed position, thereupon effecting the xed positioning or freezing o'f the microammeter |31 by the deen'ergizing ofthe solenoid |31' and a simultaneous energizing of Athes'olenoid |38.

Y Referring now to the panel arrangement of Fig. '7; thek controls' may be further explained lfor clarification of understanding. The motor'switch |485, the motor eld switch |49, and a small indicator lamp |5| are preferably wired so that whenY the motor eld switch is closed the light will be on. The rotative speed of the motor is controlled by the motor eld rheostat |52 and the speed indicator preferably recording in revbltionslpe'r' minute i's indicated at |53. The switch |54- controlsthe alternating current electromotive force which is to be applied to the photoelectric stevie circuit amplifier and falso `jto the change Vspeed amplifier sho'wn atflil 'Iand'l26 in Figs. 8` andl 9. Thel clutch solenoid switch |41 is preferably provi'ded'with asmall indicatorlamp |56,`which like Wise lightsup when the switch is in the closed position. Additional indicating lamps, designated |51 and |58, areoperated by the'switch 49, which is associated'with the clutch, so that when the latter member is'engaged the lamp |51 is lighted, but when the clutch is disengaged the lamp I 58 islightedwhichautomatically` turns off thelampll.` "t 1v It will be apparent from Figs; 10, 11, 12 and 13 that the variable velocity'impactmachine of this invention is capable of performing at least two types of tests, that is, the regular vimpact test which comprises a single striking ,dog 54, and adapted'to strikrsubstantially transversely the `specimen to be tested, whichis positioned upon an anvil, nearits middle thereby'either breaking or'bendingthe specimen.V This regular* impact testapparatus is's'hownl in detail in Figs. 10 and 11. As best shown in'Fig. '12, thefapparatus is also` adapted to make tension tests of standard test specimens,`s'uch`as that shown at |59. The

upperlpordon @fthe test specimen 1591s threaded into'a coupling V"|6|, with the other end of thecoupling receiving the'thre'aded stud 58,V also threadedly engaging the ,f internal shaft '|9.` A cross member' |62 is threaded onto the lower end of the test specimen 59.A This specimen |59 and/or r 'its crossA member |62 preferably does not rest -to a position in which `the test specimen |59 is placed closely adjacent the periphery of the rotor |4 and at a point where the testspecimen'is substantially tangentto kthe circumference of the rotor |43 A modiiied striker IM is employed to perform thetensile test on'the specimen |59. The'novel modified `form of striker |64 herewith illustrated and described 'is provided with the fork-like prongs |66 and |61,A as more 4clearly shown in Fig; 13, and thus doesnot 'actu-ally strike the test specimen. |59 but rather-hits the cross 'member |62.' In so doing it is enabled to stretch or toipull the specimen |59 apart under a combined high tension and impact load. Inasmuch as theinternal shaft Ill/must be moved further Ain the tensile testing apparatus in order-that the specimen obtain -a position .ofsubstantial tan- Fig, 17s'ho'ws the apertured trigger arm 99 with respective 1endportions 82 and 92' employed in the notched bar impact test shown in all the iigures up to and including Fig. 1l; and Fig. 18 shows the slightly modified apertured trigger arm 95" with its end portion 92 formed downwardly so that it does not engage the stop 98 until the inner shaft I9 has turnedthe desired distance to accommodate the making of the test of tensile qualities in a test specimen. Its opposite end 82 is formed similarly to the end 82 of the trigger arm 90. e

, After the completion of either test, namely the notched bar` or the tensile impact test, the broken specimens are thrown under high velocity in to the pan 32 immediately below the impact wheel |4. Here, similarly, it is preferable that the pan 32 contain or be partially filled with a sufficiently viscous medium such as grease, soap or plastic clay to absorb the blow and to prevent further marring of or damage to the severed tin of thelfracture is concerned, or making note ofthe character o'f theielongation'and bend ,of the test yspecimen if it should not break. Study of thesephysical characteristics, inconjunction with accurate knowledge ofthe energy absorbed bythe impact, supplies the testing laboratory technician with 'a suiiicientindei of'm'aterial to enable to calibrate the" machine according to'Well-known standard'impact machines of the constantspeedtype'. l

It istherefore'evident that a: novelV 'testing machine of `the type has beendeveloped in which the numerous-details of Vconstruction may be varied throughout awide range without depart` ing fro-mfthellprinciples disclosed herein. l" We therefore fdo' noti propose limiting the patent grantedA hereoni `otherwise than as necessitated byl the appended claims interpreted in light `of thefpriorart. i .L Y X 1 AVVeclaiInz` A i `1.'A-variable velocity impact testing machine for effecting-transverse,andi.tension tests com prising a? rotorvhaving a surface-portion with a different vreflection factor, impact means on the said'r'otor, means for propelling a test specimen fromv a position outsidethe path of .movement described by .the saidimpact` means to` afposition within the path of the said impactmeansand to a 'position of -rest beforebeing struck bythe said impact means and the said propelling means comprising aphotoelectric `cell operable by the surfaceportion--ofthe said rotor` having a different reflection factor.` L2..A variablelvelocity impact testing machine for effecting..transverse andtension tests comprising a rotor with a portion,of3its surfacehaving la different reflection factor, impact means on said rotor, means for propelling a test specimen froma position outside ,the path of `movement described by the impact means to a position within the path ofsaidimpact means and to a position of substantial immovability before being struckby the said impact means, thesaid means for E-propelling-,the llet Specimen comprising a photoelectric cell, operablevby the surface portion of-thesaid rotor having a different lreflection 5.0 factor, a` solenoid-` operated bythe said photoelectric 1 cell, resilient ,means normally tending' to .propel the utest. speci-men within the path ofthe said.` impact` means,and. restraining means for holding,theitestfspecimeril outside the path of said impactA means, 'said solenoid operationbeing adapted to withdraw thsaid restraining means and to permit normal action of the said resilient means.

3. A variable `velocity impact testing machine comprising variable speed propelling means, a rotor connected with the said propelling means, fixed impact means on the said rotor, solenoid actuated means for positioning a test specimen Within the arcuate path of movement of the said xed impact means, and disengageable means between the said rotor and the said propelling means cooperating with the said solenoid actuated means, whereby preliminary 'to the functioning of the said solenoid actuated specimen 7u positioning means the propelling means for the said rotor is automatically disengaged.` l

4. A variable velocity impact testing machine for effecting transverse and tension tests comprising variable speed propelling means, a rotor with light reflecting means cooperating with the by upon functioning of the said .latternieonsfhy the rotor light reflecting .means the rotative 1motion of the said rotor is substantiallynnaiected by avoidance of drag 11.11011 'the 5.341... .;I.0t 0r..

5. A variable velocity impactcst'ing machine comprising ,a variable speed propelling 1119120?, 1a rotor .cooperating with the said-propelling motor, a clutch intermediate thegsaid propelling 10129! .and rotor, electrical `solenoid .means or disengaging said clutch, striking .dog-s .on thejsaid'rotor, .a holder and electric solenoid fxneanszfor position-y ing a test specimen Within the path ,desciibedgby the said striking dogs, and a photociectic .cell excited .fby the said'rotor actuatingthe .said .electric solenoid, whereby upon :actuation ofrthe said first namedelectric solenoidmeans "by the photoelectric cell the rotativze motion .-of thesaid-rotor is unaiected and is free of engagementwith the said clutch to the eXtentthat-no mechanical energy is -thereby lostftiie` rotorrthereby operating free of the motor. f

6. A variable 4speed impact .testing machine comprising propelling means, -afxfotor driven .by the said propelling means, tthe said'rotor having impact means thereon, optical-electrical position- '1. .A variable vspeed impact testing ymachine comprising 'propelling means, ya rotor driven @by tnesaidpropeiling meansfthe said kroter-finwiihg spaced 'Projections .extending iro-m thenerinhery tl1ereof ,upositionin g means forl placing -a test specimen in the path of movement ofithegsaid I spaced Iproj ectionsthe said `pc,)sitioninsgl-mean-s in5- ciluding respectively en'anril ifor .seaport/.ing o test .sneeinnen et its. end/portions., a-holderatherefor.. andelectricallyactnated insegtionaineanseor i moving test specimenironi a position outside the nath .of the spaced .Protections of the .rotor .toe position `within thenath of the said proieotions. including means `for .holding the test .specimen relatively motionless. at the inception .of impact with the .said projections. clutch. .Ineens between the propellingmeans and the said rotor, and means for disengaging 4the said clutch means .immediately betere placing :the test specimen .in the path of movement of said projections.

v8. A variable Velocity impact testing machine for eiecting transverse and tension tests comprising a rotor, xed impact means on the said rotor, positioning means for a test specimen cooperating fwith the .said roter andthe said ,xed .impact ineens, .light reiieeting areas .on seid rotor.. a .light sonrce, and .light .sensitive .ineens coordf noted with the .inotion of .seid rotor through .light ectedfloy said areasior ectnotingsaidnositionf .ingnieans whereby engagement between the said'nnediinhectnreens .en the .rotor andthe test sheciinenV is tiined :by the .said .positioning ineens 9 .n variable Vvelocity .impact ltesting machine .for effecting transverse andtension tests .compr-.is- .ing e rotor., niied impact ineens on-thesaid rotor. positioning vmeans .for test specimen, the said positioning .Ineens cooperating with-the said rotor .and `the seid Xed impact ineens, :light reiiectine areas on said rotor., e. light source, andiigntsensi- .tive means .coordinated with the motion oi .said rotor A.through iight --.re1i.ected by .said areas :for actuating said positioning means whereby when the latter means is actuated loyilight reflected from Y.the vsaid .rotor the test specimen is positioned in the nath of movement of .the .said ininactmeahs and fis motionless'before fheingpstrilckhy the .said

impact means.

10. A Variable velocity impacttesting :machine for .eiecting transVerseand-tenscn tests comprising a rotor, Xed. striking l.edgeor edges .on the periphery .of the saidrotor, positioning means tor a test specimen, .light reiiecting vnortionsnn the said rotor, a light source, thesa-id lpositioning .means having .electrical means.. actuated through the light rei'lectingportionsof the said rotor-with the Ysaid xed ,striking .edge or edges, and said .electrical means including `light :sensitive means actua-ted by said Ylight,reiiecting portions of the said rotor for establishing the introduction of the test specimen by the. said positioning means at a position immediately -ahead .of :the approaching striking edgeor edges on the .said rotor. 

